VBox/Virtualbox how to shrink VDI image and recover/reclaim unused disk space
VBoxManage modifyvdi /path/to/your.vdi compact
I believe this should be done only when your VM is powered off, but I decided to try it with the system powered on. i wouldn't recommend it because it's dangerous even if it does work but this is a test system. For anything important/production I would always take a backup first and make sure the system is powered off.
VBoxManage modifyvdi XP-clone.vdi compact
0%...10%...20%...30%...40%...50%...60%...70%...80%...90%...100%
Tags:
vbox, virtualbox, vdi, reclaim, unused, disk, spacevboxmanage, modifyvdi, compact, vm, powered, wouldn, vboxmanage, xp, clone,